Definition
Rotation of the airplane about its longitudinal axis — the imaginary line running from the nose to the tail. Roll is controlled by the ailerons and causes one wing to move down while the other moves up, banking the airplane left or right.
Plain English
Roll is when the airplane tips one wing down and the other wing up, like leaning to the side. The pilot makes this happen by turning the control wheel or moving the stick left or right.
Context Anchor
Seen when learning how the flight controls move the airplane, especially when using the control wheel or stick to enter, correct, or stop a bank.
Derivation
From Old English 'rollian,' meaning to turn over or rotate. The word is used here in its rotational sense — the airplane rotates about its lengthwise axis, the same way a log rolls about its long axis.
Why Pilots Care
Roll is the primary way a pilot changes bank angle, which is required to turn the aircraft safely and efficiently.
Intuition Check
Roll does not mean the airplane is spinning over like a barrel unless that maneuver is intended. In normal control use, roll means the wings tilt left or right around the airplane’s nose-to-tail line.
Example Sentence 1
The pilot applied left aileron to roll the airplane into a 30-degree left bank.
Example Sentence 2
A small roll correction was needed to keep the wings level while flying through the gusty wind.